– A point at which it is impossible to reverse one’s actions or return to one’s starting point.
– the halfway point; the point at which it is too late to turn back. (Often with past.)
– The place in a course of action beyond which reversal is not possible. For example, Once the contract is signed, we’ve reached the point of no return. This expression comes from aviation, where it signifies the point where an aircraft does not have enough fuel to return to the starting point. [c. 1940]
– the point in a journey or enterprise at which it becomes essential or more practical to continue to the end.
– the time when you must continue with what you have decided to do, because it is not possible to get back to an earlier situation
– A critical point that, if passed, allows for no reversal of direction or decision
“The point of no return ( PNR or PONR) is the point beyond which one must continue on one’s current course of action because turning back is dangerous, physically impossible or difficult, or prohibitively expensive. The point of no return can be a calculated point during a continuous action. A particular irreversible action can be a point of no return.”
“ The phrase “point of no return” originated as a technical term in air navigation to refer to the time and/or location during a flight at which the aircraft no longer has enough fuel to return to its originating airfield. Important decisions may need to be made prior to the point of no return, since it will be unsafe to turn around and fly back if the pilot changes their mind after that point. Otherwise, it may correspond to the aircraft’s maximal safe range in a situation where the only possible landing site is the takeoff site, for example in the case of an aircraft attached to an aircraft carrier that is underway and distant from any airfield. In those conditions, an aircraft must always have enough fuel for a return flight, so the “point of no return” may represent the point before which the pilot must return or else risk catastrophe.” https://en.wikipedia.org/wiki/Point_of_no_return
There are a number of phrases with similar or related meaning:
The Point of Safe Return (PSR) is the last point on a route at which it is possible to safely return to the departure airfield with the required fuel reserves still available in the tanks. Continuing past the PSR, the aircraft must either land at its intended destination or divert and land at another nearby airfield should an emergency arise.
– “Beyond a certain point there is no return. This point has to be reached.”
– “Crossing the Rubicon” is a metaphor for deliberately proceeding past a point of no return. The phrase originates with Julius Caesar’s seizure of power in the Roman Republic in 49 BC. Roman generals were strictly forbidden from bringing their troops into the home territory of the Republic in Italy. On 10 January, Caesar led his army across the Rubicon River, crossing from the province of Cisalpine Gaul into Italy. After this, if he did not triumph, he would be executed. Therefore, the term “the Rubicon” is used as a synonym to the “point of no return”.
– “alea iacta est” (“The die is cast”), which is reportedly what Caesar said at the crossing of the Rubicon. This metaphor comes from gambling with dice: once the die or dice have been thrown, all bets are irrevocable, even before the dice have come to rest.
The following expressions also express the idea of a point of no return.
– “Burn one’s bridges”. This expression is derived from the idea of burning down a bridge after crossing it during a military campaign, leaving no choice but to continue the march. Figuratively, it means to commit oneself to a particular course of action by making an alternative course impossible. It is most often used in reference to deliberately alienating persons or institutions whose cooperation is required for some action. For instance, “On my last day at my old job, I told my boss what I really think about the company. I guess I burned my bridges.”
– “Burn one’s boats”. This is a variation of “burning one’s bridges”, and alludes to certain famous incidents where a commander, having landed in a hostile country, ordered his men to destroy their ships, so that they would have to conquer the country or be killed.
– “Break the kettles and sink the boats (破釜沉舟)”. This is an ancient Chinese saying, which refers to Xiang Yu’s order at the Battle of Julu (207 BC); by fording a river and destroying all means of re-crossing it, he committed his army to a struggle to the end with the Qin and eventually achieved victory.
– “Fighting a battle with one’s back facing a river” (背水一戰). A similar saying from the same period, which originated in Han Xin’s order at the Battle of Jingxing (204 BCE).
– “Fait accompli” (“accomplished deed”, from the verb “faire”, to do), a term of French origin denoting an irreversible deed, a done deal.
– “Can’t unring a bell”, North American English phrase also denoting an irreversible deed.
– “Line in the sand” – an expression to mean that once a decision is made it is not possible to be reversed.
– “Red line” (phrase) – an expression to mean that if a certain extreme action is taken, consequences would be incurred.
– “The arrow has been launched from the bow”. A Turkish expression meaning a path of no return has been taken.